There are currently two issues:
- Every time you enable or disable a plugin in CompizConfig Settings Manager (
ccsm), Compiz (and therefore Unity) will crash.
- CompizConfig Settings Manager fails to replace the Wall plugin with the Desktop Cube plugin.
One really ugly workaround is to manually set the plugins via the commandline:
gconftool-2 --type l --list-type string --set /apps/compiz-1/general/screen0/options/active_plugins "[core,bailer,detection,composite,opengl,compiztoolbox,decor,move,vpswitch,place,mousepoll,resize,staticswitcher,imgpng,regex,gnomecompat,grid,snap,zoom,session,animation,workarounds,fade,cube,expo,scale,rotate,unityshell,unitymtgrabhandles]" && (unity &)
Running this will set the plugins to Unity's default, but will replace Wall with Desktop Cube and Rotate Cube.
Unity's default is to have 2x2 desktops, but for the cube you'll likely want 4x1 desktops. You can change this in the General Options plugin in the CompizConfig Settings Manager. Go to the Desktop Size tab, and change Horizontal Virtual Size to 4 and Vertical Virtual Size to 1.
You should now be able to rotate the cube using the default shortcuts:
Alt + Ctrl + ← and Alt + Ctrl + →